BEIRUT — The death toll in Syria's three-year conflict has exceeded 160,000, an activist group said Monday, a harrowing figure that reflects the country's relentless bloodletting that appears no closer to a resolution.

The Britain-based Syrian Observatory for Human Rights said it has documented 162,402 deaths since the uprising against President Bashar Assad's government began in March 2011.

The figure includes civilians, rebels and members of the Syrian military, the Observatory said. It also includes militiamen, such as Lebanese Hezbollah members, who have been fighting alongside Assad's forces, and foreign fighters battling with the rebels for Assad's ouster.

The Observatory remains the sole organization providing a reliable tally of Syria's dead.

The U.N. has stopped updating its own tally of the Syrian dead, saying it can no longer verify the sources of information. The world body's last count in late July was 100,000 dead.